For more than a decade flatbed trailers for containers have played an important role in transportation. Containers are sized uniformly and hoisted onto or down flatbed trailers by cranes without manual work, and with much convenience. But the most important thing in the hoisting process is that the goods or products put in containers should not be moved or collide with one another. Besides, goods that can endure shocks such as mineral ore, scrap, coal, grain, etc. have to be loaded or unloaded with manual work. For example, one container for loading 22 tons of aluminum scrap needs 10 hours by 5 workers and a lift truck and for unloading the same takes 8 hours by 3 workers and a lift truck. This kind of loading and unloading method not merely wastes man power but time, to the result of inconvenience and being uneconomical.